Moose PVC Bird Nest Box

Why my interest in a new nest box design?

I inherited an interest in birds from my father, whose family grew up next door to a bird expert. Ruth Thomas studied and banded birds and wrote, “Crip, Come Home” as well as, “Brush Goat, Milk Goat” and a weekly column on birds in the 1940s in the Arkansas Democrat Newspaper. Many of my relatives have fed birds (including hummingbirds) and land-lorded Purple Martins and Bluebirds. I finally upgraded to property that lent itself to land-lording in 1998. My plastic Purple Martin gourds last forever, while my Bluebird houses have been replaced many times over the years. In researching PVC as an option, I ran into the Gilbertson design but thought it was overly complex and had some risk for dropping the nest-box onto the ground, so I designed my own nest-boxes and put them into use in 2016. With only 1.5 acres for 5 nest-boxes, 2017 saw 13 Bluebirds and 20 House Wrens fledged from the new boxes.

Advantages:

PVC post – Entire assembly can be moved inside for winter if desired (may extend product life)

PVC vs Wood Nest Box – Cheaper, fewer parts, easier to make and assemble, longer life

Moose vs Gilbertson – Cheaper, fewer parts, easier to make and assemble, heavier and better insulated

Supported from bottom, so no risk of nest-box falling from a top-suspension design

Slit vs Round opening – No sparrows, easier feeding of older nestlings

Mobile, vented floor – No moisture, fly larvae may fall through, easy to expel spent nest

Removable Roof – Easy viewing and photography of nestlings

Removable Nest Box – Easy viewing and cleaning

Bucket Guard – Cheaper than metal and no seams with exposed screws for climbing snakes

3.5”x36” Steel U-Post

2”x5’ PVC pipe Post

4” to 2” PVC adapter

4”x6” PVC pipe Nest Box

4” Qwik Cap

3.75x3.75” hardware “cloth” floor

6” carriage bolt floor anchor

.67”x11.25”x12” roof

5-gallon bucket predator guard

Table saw and/or Sabre Saw

Xacto Knife

Trauma Sheers or Tin Snips

2.25" hole saw

Hand Drill and Screwdriver

Post Driver or Sledge Hammer

Pre-assembly instructions (see pictures):

1) Cut 11-12” Square Roof and glue it to rubber Quick Cap

(gorilla glue is good but expands when curing; use knife when done to cut away excess glue)

2) Cut two pieces of hardware cloth and assemble with 6-8” centered bolt

Bolt works as center-weight to keep floor from tilting and as plunger to expel spent nests

3) Cut 4” PVC to 6” length; cut 2.5x1.25” entrance slot into Quick Cap with Xacto Knife

4) Put Quick Cap onto Nest-Box and trace opening to cut matching entrance to Nest-Box

5) Cut two 1.75”, vertical, ventilation slits opposite the entrance slot from upper edge of Nest-Box

(slits will extend ~1/2” below Quick Cap when roof is in place)

5) Cut 2” PVC post to ~5’ length

6) If planning to add predator guard inverted bucket

a. Use hole saw to cut 2.25” hole in bottom of bucket

b. Measure ~11” down from top of post and wrap masking tape around post; make it level

c. Drill 1st hole along upper edge of tape

d. Measure 2.5” to left and right of hole to mark 2nd and 3rd holes for screws

e. Screw in the three short screw so screw-heads project a few mm

1) Choose a location

2) Place a post smaller than 2”; U-posts and retired chain-link posts work well

3) Cover with 2” PVC post ~5’ tall

4) Slide optional inverted bucket guard until suspended by 3 screws in post

5) Add 2” to 4” PVC converter

6) Add 4” PVC Nest Box

7) Add hardware cloth base to Nest Box and cover with pine-needles

8) Add 4” Qwik Cap to top of Nest Box with entry slit matching Nest Box slit

(11-12” roof glued to top of Qwik Cap in pre-assembly)

10) Gelstain post & nest if wanting to blend better with landscape

(Stain inside of nestbox during pre-assembly if wanting darker interior)

With just one nest box, I usually get 2-3 broods of bluebirds each year with an average of 5 eggs per brood. With several boxes, I often have two active nests at a time despite the territorial nature of bluebirds in a 1.5 acre space. I can have 10-20 babies fledging per year, so over the past 20 years here, we have had more than 300 bluebirds fledge. The chickadees and house-wrens also like the boxes.

This year with the new box design, we fledged six chickadees (only one brood per year), 20 house-wrens, and 13 bluebirds. The wrens and bluebirds are quite welcome, since anything that eats insects on my property is an asset.

There were no snake attacks. I have had three over the years, so decided to add the buckets during my upgrade this year. We have black rat snakes that are quite talented in getting to nests, and we also have raccoons and squirrels. The slot near the roof has kept out the starlings, but in the wooden boxes, we still got sparrows at times. This year, the new design didn't seem to interest the sparrows at all.

This file is a Word document with all of the info from this instructable, so it would be easy to download for reference offline while building your own nest box.